An adult pet mongrel died on Monday about 24 hours after it showed signs of poisoning, making it the 11th dog from a remote village in Hong Kong to die over the weekend, an animal welfare group has said.

The Society for the Prevention of Cruelty to Animals (SPCA) said the incidents took place near San Tau village on Lantau Island, while police said they received three reports of animal cruelty.

A police source said: “We don’t rule out the possibility the three cases were linked and the dogs were poisoned because it was unusual for so many dogs to die in one location in such a short period.

“Initial examination showed the dogs had no obvious signs of injury and they suffered symptoms of poisoning such as vomiting before they died,” he said.

The Agriculture, Fisheries and Conservation Department would carry out postmortem examinations and toxicology tests to establish the cause of death.

The source said it was possible the dogs were poisoned, as some of the animals were able to wander freely in San Tau village and the section of Tung O Ancient Trail that connects the village and Tin Hau Temple in Tung Chung.

Police said officers searched the area but no poison bait was found.

On Monday afternoon, hygiene officers were called in to clear the trail and police put up posters along the path to warn pet owners of the incidents. They appealed for anyone with information to call officers at 3661 1930 and 6148 0688.

At the same time, a team of detectives went door to door at the 60 or so households to gather information. About 300 people live in the village.

Police said the first call came from a 45-year-old San Tau village resident on Saturday who said six of his pet dogs had died, with two others missing. The dead animals were a female adult Yorkshire terrier, a male adult mongrel and four puppies aged four to six weeks. The two missing dogs are an adult Rottweiler and an adult mongrel.

Subsequently, another three dogs were taken to a veterinary surgeon in Tung Chung after suffering signs of poisoning. All later died.

The owner of two of the three dogs told police he walked his pets on the trail on Saturday morning and the dogs fell ill after returning to his home in the nearby Shek Lau Po village.

Another San Tau village resident then called police on Sunday morning after one of her two dogs died and the other was taken ill. The male adult mongrel was taken to the SPCA clinic in Wan Chai for treatment. It died on Monday morning.

Police said the deaths were classified as cruelty to animals and detectives from the Lantau police district are investigating. So far, no one has been arrested.

In Hong Kong, cruelty to animals carries a maximum sentence of three years’ imprisonment and a fine of up to HK$200,000.

A spokeswoman for the SPCA urged pet owners to be extremely careful when walking their pets in the area and to keep their pets on a leash if necessary. It asked that those who see anything suspicious call its hotline at 2711 1000.